<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package	Zend_Search_Lucene
 * @subpackage Document
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license	http://framework.zend.com/license/new-bsd	 New BSD License
 */


/** Zend_Search_Lucene_Document */
require_once 'Zend/Search/Lucene/Document.php';


/**
 * HTML document.
 *
 * @category   Zend
 * @package	Zend_Search_Lucene
 * @subpackage Document
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license	http://framework.zend.com/license/new-bsd	 New BSD License
 */
class Zend_Search_Lucene_Document_Html extends Zend_Search_Lucene_Document
{
	/**
	 * List of document links
	 *
	 * @var array
	 */
	private $_links = array();

	/**
	 * List of document header links
	 *
	 * @var array
	 */
	private $_headerLinks = array();

	/**
	 * Stored DOM representation
	 *
	 * @var DOMDocument
	 */
	private $_doc;

	/**
	 * Object constructor
	 *
	 * @param string  $data
	 * @param boolean $isFile
	 * @param boolean $storeContent
	 */
	private function __construct($data, $isFile, $storeContent)
	{
		$this->_doc = new DOMDocument();
		$this->_doc->substituteEntities = true;

		if ($isFile) {
			@$this->_doc->loadHTMLFile($data);
		} else{
			@$this->_doc->loadHTML($data);
		}

		$xpath = new DOMXPath($this->_doc);

		$docTitle = '';
		$titleNodes = $xpath->query('/html/head/title');
		foreach ($titleNodes as $titleNode) {
			// title should always have only one entry, but we process all nodeset entries
			$docTitle .= $titleNode->nodeValue . ' ';
		}
		$this->addField(Zend_Search_Lucene_Field::Text('title', $docTitle, $this->_doc->actualEncoding));

		$metaNodes = $xpath->query('/html/head/meta[@name]');
		foreach ($metaNodes as $metaNode) {
			$this->addField(Zend_Search_Lucene_Field::Text($metaNode->getAttribute('name'),
														   $metaNode->getAttribute('content'),
														   $this->_doc->actualEncoding));
		}

		$docBody = '';
		$bodyNodes = $xpath->query('/html/body');
		foreach ($bodyNodes as $bodyNode) {
			// body should always have only one entry, but we process all nodeset entries
			$this->_retrieveNodeText($bodyNode, $docBody);
		}
		if ($storeContent) {
			$this->addField(Zend_Search_Lucene_Field::Text('body', $docBody, $this->_doc->actualEncoding));
		} else {
			$this->addField(Zend_Search_Lucene_Field::UnStored('body', $docBody, $this->_doc->actualEncoding));
		}

		$linkNodes = $this->_doc->getElementsByTagName('a');
		foreach ($linkNodes as $linkNode) {
			if (($href = $linkNode->getAttribute('href')) != '') {
				$this->_links[] = $href;
			}
		}
		$this->_links = array_unique($this->_links);

		$linkNodes = $xpath->query('/html/head/link');
		foreach ($linkNodes as $linkNode) {
			if (($href = $linkNode->getAttribute('href')) != '') {
				$this->_headerLinks[] = $href;
			}
		}
		$this->_headerLinks = array_unique($this->_headerLinks);
	}

	/**
	 * Get node text
	 *
	 * We should exclude scripts, which may be not included into comment tags, CDATA sections,
	 *
	 * @param DOMNode $node
	 * @param string &$text
	 */
	private function _retrieveNodeText(DOMNode $node, &$text)
	{
		if ($node->nodeType == XML_TEXT_NODE) {
			$text .= $node->nodeValue ;
			$text .= ' ';
		} else if ($node->nodeType == XML_ELEMENT_NODE  &&  $node->nodeName != 'script') {
			foreach ($node->childNodes as $childNode) {
				$this->_retrieveNodeText($childNode, $text);
			}
		}
	}

	/**
	 * Get document HREF links
	 *
	 * @return array
	 */
	public function getLinks()
	{
		return $this->_links;
	}

	/**
	 * Get document header links
	 *
	 * @return array
	 */
	public function getHeaderLinks()
	{
		return $this->_headerLinks;
	}

	/**
	 * Load HTML document from a string
	 *
	 * @param string $data
	 * @param boolean $storeContent
	 * @return Zend_Search_Lucene_Document_Html
	 */
	public static function loadHTML($data, $storeContent = false)
	{
		return new Zend_Search_Lucene_Document_Html($data, false, $storeContent);
	}

	/**
	 * Load HTML document from a file
	 *
	 * @param string $file
	 * @param boolean $storeContent
	 * @return Zend_Search_Lucene_Document_Html
	 */
	public static function loadHTMLFile($file, $storeContent = false)
	{
		return new Zend_Search_Lucene_Document_Html($file, true, $storeContent);
	}


	/**
	 * Highlight text in text node
	 *
	 * @param DOMText $node
	 * @param array   $wordsToHighlight
	 * @param string  $color
	 */
	public function _highlightTextNode(DOMText $node, $wordsToHighlight, $color)
	{
		$analyzer = Zend_Search_Lucene_Analysis_Analyzer::getDefault();
		$analyzer->setInput($node->nodeValue, $this->_doc->encoding);

		$matchedTokens = array();

		while (($token = $analyzer->nextToken()) !== null) {
			if (isset($wordsToHighlight[$token->getTermText()])) {
				$matchedTokens[] = $token;
			}
		}

		if (count($matchedTokens) == 0) {
			return;
		}

		$matchedTokens = array_reverse($matchedTokens);

		foreach ($matchedTokens as $token) {
			// Cut text after matched token
			$node->splitText($token->getEndOffset());

			// Cut matched node
			$matchedWordNode = $node->splitText($token->getStartOffset());

			$highlightedNode = $this->_doc->createElement('b', $matchedWordNode->nodeValue);
			$highlightedNode->setAttribute('style', 'color:black;background-color:' . $color);

			$node->parentNode->replaceChild($highlightedNode, $matchedWordNode);
		}
	}


	/**
	 * highlight words in content of the specified node
	 *
	 * @param DOMNode $contextNode
	 * @param array $wordsToHighlight
	 * @param string $color
	 */
	public function _highlightNode(DOMNode $contextNode, $wordsToHighlight, $color)
	{
		$textNodes = array();

		if (!$contextNode->hasChildNodes()) {
			return;
		}

		foreach ($contextNode->childNodes as $childNode) {
			if ($childNode->nodeType == XML_TEXT_NODE) {
				// process node later to leave childNodes structure untouched
				$textNodes[] = $childNode;
			} else {
				// Skip script nodes
				if ($childNode->nodeName != 'script') {
					$this->_highlightNode($childNode, $wordsToHighlight, $color);
				}
			}
		}

		foreach ($textNodes as $textNode) {
			$this->_highlightTextNode($textNode, $wordsToHighlight, $color);
		}
	}



	/**
	 * Highlight text with specified color
	 *
	 * @param string|array $words
	 * @param string $color
	 * @return string
	 */
	public function highlight($words, $color = '#66ffff')
	{
		if (!is_array($words)) {
			$words = array($words);
		}
		$wordsToHighlight = array();

		$analyzer = Zend_Search_Lucene_Analysis_Analyzer::getDefault();
		foreach ($words as $wordString) {
			$wordsToHighlight = array_merge($wordsToHighlight, $analyzer->tokenize($wordString));
		}

		if (count($wordsToHighlight) == 0) {
			return $this->_doc->saveHTML();
		}

		$wordsToHighlightFlipped = array();
		foreach ($wordsToHighlight as $id => $token) {
			$wordsToHighlightFlipped[$token->getTermText()] = $id;
		}

		$xpath = new DOMXPath($this->_doc);

		$matchedNodes = $xpath->query("/html/body");
		foreach ($matchedNodes as $matchedNode) {
			$this->_highlightNode($matchedNode, $wordsToHighlightFlipped, $color);
		}

	}

	/**
	 * Get HTML
	 *
	 * @return string
	 */
	public function getHTML()
	{
		return $this->_doc->saveHTML();
	}
}

